There are numerous types of semiconductor devices, including rectifiers, transistors, current limiters, thermistors, p-n junctions, field-effect diodes, Schottky diodes, and so forth. In each semiconductor device, a semiconductor material is combined with one or more metals or insulators to form the device. Semiconductor devices can be prepared or manufactured by known methods such as, for example, those described by Peter Van Zant in Microchip Fabrication, Fourth Edition, McGraw-Hill, New York (2000).
A particularly useful type of transistor, the thin-film transistor (TFT), generally includes a gate electrode, a gate dielectric on the gate electrode, a source electrode and a drain electrode adjacent to the gate dielectric, and a semiconductor layer adjacent to the gate dielectric and adjacent to the source and drain electrodes (see, for example, S. M. Sze, Physics of Semiconductor Devices, 2nd edition, John Wiley and Sons, page 492). These components can be assembled in a variety of configurations. An organic thin-film transistor (OTFT) is characterized by having an organic semiconductor layer.
U.S. Pat. No. 6,452,207 discloses a class of fluorene oligomer compounds and describes a thin film transistor device, which comprises a semiconductor layer of fluorene oligomer.
Other known organic semiconductors include regioregular poly(3-alkylthiophenes), oligothiophene derivatives, and fused aromatic compounds such as pentacene and tetracene.
US2004/0067387 discloses substituted anthracenes that exhibit electroluminescent properties. This published patent application also describes organic electroluminescent devices and a method for manufacturing such devices.
The composition, fabrication, and operation of field effect transistors are described in Bao et al., U.S. Pat. No. 6,107,117, the disclosure of which is incorporated herein by reference.
To enable the production of low-cost integrated circuits (IC) for applications such as electronic devices, smart cards, electronic tags, and displays, there exists a need for semiconductor devices that are fabricated from stable organic compounds that also possess desirable semiconductor properties, e.g., high mobility and a high current on/off ratio. Furthermore, there is a need for highly stable compounds that can be incorporated into TFTs at low substrate temperatures and do not need to be handled in an inert atmosphere during the fabrication of TFTs. The present invention is directed to these, and other, important ends.